In a micro-machining or processing such as, for example, etching, deposition, oxidation, sputtering, in a manufacturing process of a semiconductor device or a flat panel display (FPD), plasma is used so as to cause a processing gas to perform a good reaction at a relatively low temperature. In order to generate plasma, a conventional plasma processing apparatus excites and discharges a processing gas within a vacuum processing container by using a high frequency wave or a microwave. The processing gas may be discharged by a high frequency wave in various types such as, for example, a capacitively coupled type discharge in which a high frequency wave is applied between parallel plate electrodes provided within the processing container, and an inductively coupled type discharge in which a high frequency wave is applied to a coil attached spirally or helically around the processing container.
The plasma processing apparatus is configured to apply a high frequency wave of a relatively low frequency to an electrode of a mounting table (susceptor) on which a substrate is placed within a chamber in order to control energy of ions incident on a substrate to be processed from plasma.
The plasma processing apparatus uses various high frequency waves in generating plasma or controlling energy of ions incident on a substrate to be processed from plasma, as described above. Accordingly, a high frequency power feeding line configured to supply a high frequency wave to the processing container is provided such that a predetermined high frequency wave propagation path is set within the processing container. In general, the high frequency power feeding line or the high frequency wave propagation path of the plasma processing apparatus is configured to reach a predetermined ground potential member from a high frequency power source via an electrode within the chamber, and in the middle of the high frequency power feeding line or the high frequency wave propagation path, at least one member having a capacitive or inductive impedance is provided.
For example, a substrate may be held by an electrostatic chuck within the processing container. The electrostatic chuck is a dielectric layer having a conductor layer (e.g., an internal electrode) enclosed therein, and is disposed on a main surface of the susceptor (e.g., at a surface facing the plasma). Then, a predetermined DC voltage is applied to the internal electrode such that the substrate is held by an electrostatic attraction force generated between the substrate and the dielectric layer. As described above, when a high frequency wave for ion attraction is applied to the electrode of the mounting table, the high frequency wave is irradiated to a plasma generating space or a processing space through the electrostatic chuck and the substrate. Here, a considerable high frequency voltage (e.g., 1,000 V or more) is applied to a dielectric material (a capacitive member) of the electrostatic chuck.
In the plasma processing apparatus, a substrate temperature at the time of plasma processing may be controlled at a high response speed. In general, a heater system is employed in which a heating element configured to generate heat by energization is embedded in the electrostatic chuck or the susceptor so as to control joule heat generated by the heating element. In such a heater system, when noise of a high frequency wave introduced into a heater power feeding line through the heating element embedded in the susceptor reaches a heater power source, the operation or performance of the heater power source may be impaired. Therefore, a filter configured to attenuate or block the noise of the high frequency wave on the heater power feeding line is provided. In general, a filter of this type is provided with a coil having a very high inductance. The coil (an inductive member) is also applied with a considerable high frequency voltage (e.g., 1,000 V or more). See, for example, Japanese Patent Laid-Open Publication No. 2009-99858.